Remove most build-time require-calls from the src/display/-folder

By leveraging import maps we can get rid of *most* of the remaining `require`-calls in the `src/display/`-folder, since we should strive to use modern `import`-statements wherever possible.
The only remaining cases are Node.js-specific dependencies, since those seem very difficult to convert unless we start producing a bundle *specifically* for Node.js environments.

.eslintrc

@@ -42,7 +42,7 @@
     "import/no-mutable-exports": "error",
     "import/no-self-import": "error",
     "import/no-unresolved": ["error", {
-      "ignore": ["pdfjs", "pdfjs-lib", "pdfjs-web", "web"]
+      "ignore": ["display", "pdfjs", "pdfjs-lib", "pdfjs-web", "web"]
     }],
     "mozilla/avoid-removeChild": "error",
     "mozilla/use-includes-instead-of-indexOf": "error",

gulpfile.mjs

@@ -239,6 +239,14 @@ function createWebpackConfig(
     "pdfjs-web": "web",
     "pdfjs-lib": "web/pdfjs",
   };
+  const libraryAlias = {
+    "display-fetch_stream": "src/display/stubs.js",
+    "display-l10n_utils": "src/display/stubs.js",
+    "display-network": "src/display/stubs.js",
+    "display-node_stream": "src/display/stubs.js",
+    "display-node_utils": "src/display/stubs.js",
+    "display-svg": "src/display/stubs.js",
+  };
   const viewerAlias = {
     "web-annotation_editor_params": "web/annotation_editor_params.js",
     "web-com": "",
@@ -256,9 +264,19 @@ function createWebpackConfig(
     "web-toolbar": "web/toolbar.js",
   };
   if (bundleDefines.CHROME) {
+    libraryAlias["display-fetch_stream"] = "src/display/fetch_stream.js";
+    libraryAlias["display-network"] = "src/display/network.js";
+
     viewerAlias["web-com"] = "web/chromecom.js";
     viewerAlias["web-print_service"] = "web/pdf_print_service.js";
   } else if (bundleDefines.GENERIC) {
+    libraryAlias["display-fetch_stream"] = "src/display/fetch_stream.js";
+    libraryAlias["display-l10n_utils"] = "web/l10n_utils.js";
+    libraryAlias["display-network"] = "src/display/network.js";
+    libraryAlias["display-node_stream"] = "src/display/node_stream.js";
+    libraryAlias["display-node_utils"] = "src/display/node_utils.js";
+    libraryAlias["display-svg"] = "src/display/svg.js";
+
     viewerAlias["web-com"] = "web/genericcom.js";
     viewerAlias["web-print_service"] = "web/pdf_print_service.js";
   } else if (bundleDefines.MOZCENTRAL) {
@@ -274,7 +292,7 @@ function createWebpackConfig(
     }
     viewerAlias["web-com"] = "web/firefoxcom.js";
   }
-  const alias = { ...basicAlias, ...viewerAlias };
+  const alias = { ...basicAlias, ...libraryAlias, ...viewerAlias };
   for (const key in alias) {
     alias[key] = path.join(__dirname, alias[key]);
   }
@@ -1575,6 +1593,12 @@ function buildLibHelper(bundleDefines, inputStream, outputDir) {
     defines: bundleDefines,
     map: {
       "pdfjs-lib": "../pdf",
+      "display-fetch_stream": "./fetch_stream",
+      "display-l10n_utils": "../web/l10n_utils",
+      "display-network": "./network",
+      "display-node_stream": "./node_stream",
+      "display-node_utils": "./node_utils",
+      "display-svg": "./svg",
     },
   };
   const licenseHeaderLibre = fs

src/display/annotation_layer.js

@@ -39,6 +39,7 @@ import {
 } from "./display_utils.js";
 import { AnnotationStorage } from "./annotation_storage.js";
 import { ColorConverters } from "../shared/scripting_utils.js";
+import { NullL10n } from "display-l10n_utils";
 import { XfaLayer } from "./xfa_layer.js";
 
 const DEFAULT_TAB_INDEX = 1000;
@@ -2872,7 +2873,6 @@ class AnnotationLayer {
       typeof PDFJSDev !== "undefined" &&
       PDFJSDev.test("GENERIC && !TESTING")
     ) {
-      const { NullL10n } = require("pdfjs-web/l10n_utils.js");
       this.l10n ||= NullL10n;
     }
     if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("TESTING")) {

src/display/api.js

@@ -58,12 +58,22 @@ import {
   StatTimer,
 } from "./display_utils.js";
 import { FontFaceObject, FontLoader } from "./font_loader.js";
+import {
+  NodeCanvasFactory,
+  NodeCMapReaderFactory,
+  NodeFilterFactory,
+  NodeStandardFontDataFactory,
+} from "display-node_utils";
 import { CanvasGraphics } from "./canvas.js";
 import { GlobalWorkerOptions } from "./worker_options.js";
 import { MessageHandler } from "../shared/message_handler.js";
 import { Metadata } from "./metadata.js";
 import { OptionalContentConfig } from "./optional_content_config.js";
 import { PDFDataTransportStream } from "./transport_stream.js";
+import { PDFFetchStream } from "display-fetch_stream";
+import { PDFNetworkStream } from "display-network";
+import { PDFNodeStream } from "display-node_stream";
+import { SVGGraphics } from "display-svg";
 import { XfaText } from "./xfa_text.js";
 
 const DEFAULT_RANGE_CHUNK_SIZE = 65536; // 2^16 = 65536
@@ -72,54 +82,21 @@ const DELAYED_CLEANUP_TIMEOUT = 5000; // ms
 
 const DefaultCanvasFactory =
   typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
-    ? require("./node_utils.js").NodeCanvasFactory
+    ? NodeCanvasFactory
     : DOMCanvasFactory;
 const DefaultCMapReaderFactory =
   typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
-    ? require("./node_utils.js").NodeCMapReaderFactory
+    ? NodeCMapReaderFactory
     : DOMCMapReaderFactory;
 const DefaultFilterFactory =
   typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
-    ? require("./node_utils.js").NodeFilterFactory
+    ? NodeFilterFactory
     : DOMFilterFactory;
 const DefaultStandardFontDataFactory =
   typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
-    ? require("./node_utils.js").NodeStandardFontDataFactory
+    ? NodeStandardFontDataFactory
     : DOMStandardFontDataFactory;
 
-let createPDFNetworkStream;
-if (typeof PDFJSDev === "undefined") {
-  const streamsPromise = Promise.all([
-    import("./network.js"),
-    import("./fetch_stream.js"),
-  ]);
-
-  createPDFNetworkStream = async params => {
-    const [{ PDFNetworkStream }, { PDFFetchStream }] = await streamsPromise;
-
-    return isValidFetchUrl(params.url)
-      ? new PDFFetchStream(params)
-      : new PDFNetworkStream(params);
-  };
-} else if (PDFJSDev.test("GENERIC || CHROME")) {
-  if (PDFJSDev.test("GENERIC") && isNodeJS) {
-    const { PDFNodeStream } = require("./node_stream.js");
-
-    createPDFNetworkStream = params => {
-      return new PDFNodeStream(params);
-    };
-  } else {
-    const { PDFNetworkStream } = require("./network.js");
-    const { PDFFetchStream } = require("./fetch_stream.js");
-
-    createPDFNetworkStream = params => {
-      return isValidFetchUrl(params.url)
-        ? new PDFFetchStream(params)
-        : new PDFNetworkStream(params);
-    };
-  }
-}
-
 /**
  * @typedef { Int8Array | Uint8Array | Uint8ClampedArray |
  *            Int16Array | Uint16Array |
@@ -448,6 +425,19 @@ function getDocument(src) {
           if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
             throw new Error("Not implemented: createPDFNetworkStream");
           }
+          const createPDFNetworkStream = params => {
+            if (
+              typeof PDFJSDev !== "undefined" &&
+              PDFJSDev.test("GENERIC") &&
+              isNodeJS
+            ) {
+              return new PDFNodeStream(params);
+            }
+            return isValidFetchUrl(params.url)
+              ? new PDFFetchStream(params)
+              : new PDFNetworkStream(params);
+          };
+
           networkStream = createPDFNetworkStream({
             url,
             length,
@@ -3454,5 +3444,6 @@ export {
   PDFWorker,
   PDFWorkerUtil,
   RenderTask,
+  SVGGraphics,
   version,
 };

src/display/node_stream.js

@@ -31,14 +31,10 @@ if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
   );
 }
 
-const fs = __non_webpack_require__("fs");
-const http = __non_webpack_require__("http");
-const https = __non_webpack_require__("https");
-const url = __non_webpack_require__("url");
-
 const fileUriRegex = /^file:\/\/\/[a-zA-Z]:\//;
 
 function parseUrl(sourceUrl) {
+  const url = __non_webpack_require__("url");
   const parsedUrl = url.parse(sourceUrl);
   if (parsedUrl.protocol === "file:" || parsedUrl.host) {
     return parsedUrl;
@@ -344,11 +340,13 @@ class PDFNodeStreamFullReader extends BaseFullReader {
 
     this._request = null;
     if (this._url.protocol === "http:") {
+      const http = __non_webpack_require__("http");
       this._request = http.request(
         createRequestOptions(this._url, stream.httpHeaders),
         handleResponse
       );
     } else {
+      const https = __non_webpack_require__("https");
       this._request = https.request(
         createRequestOptions(this._url, stream.httpHeaders),
         handleResponse
@@ -391,11 +389,13 @@ class PDFNodeStreamRangeReader extends BaseRangeReader {
 
     this._request = null;
     if (this._url.protocol === "http:") {
+      const http = __non_webpack_require__("http");
       this._request = http.request(
         createRequestOptions(this._url, this._httpHeaders),
         handleResponse
       );
     } else {
+      const https = __non_webpack_require__("https");
       this._request = https.request(
         createRequestOptions(this._url, this._httpHeaders),
         handleResponse
@@ -420,6 +420,7 @@ class PDFNodeStreamFsFullReader extends BaseFullReader {
       path = path.replace(/^\//, "");
     }
 
+    const fs = __non_webpack_require__("fs");
     fs.lstat(path, (error, stat) => {
       if (error) {
         if (error.code === "ENOENT") {
@@ -449,6 +450,7 @@ class PDFNodeStreamFsRangeReader extends BaseRangeReader {
       path = path.replace(/^\//, "");
     }
 
+    const fs = __non_webpack_require__("fs");
     this._setReadableStream(fs.createReadStream(path, { start, end: end - 1 }));
   }
 }

src/display/stubs.js

@@ -0,0 +1,36 @@
+/* Copyright 2023 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const NodeCanvasFactory = null;
+const NodeCMapReaderFactory = null;
+const NodeFilterFactory = null;
+const NodeStandardFontDataFactory = null;
+const NullL10n = null;
+const PDFFetchStream = null;
+const PDFNetworkStream = null;
+const PDFNodeStream = null;
+const SVGGraphics = null;
+
+export {
+  NodeCanvasFactory,
+  NodeCMapReaderFactory,
+  NodeFilterFactory,
+  NodeStandardFontDataFactory,
+  NullL10n,
+  PDFFetchStream,
+  PDFNetworkStream,
+  PDFNodeStream,
+  SVGGraphics,
+};

src/pdf.js

@@ -50,6 +50,7 @@ import {
   getDocument,
   PDFDataRangeTransport,
   PDFWorker,
+  SVGGraphics,
   version,
 } from "./display/api.js";
 import {
@@ -78,11 +79,6 @@ const pdfjsVersion =
 const pdfjsBuild =
   typeof PDFJSDev !== "undefined" ? PDFJSDev.eval("BUNDLE_BUILD") : void 0;
 
-const SVGGraphics =
-  typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC")
-    ? require("./display/svg.js").SVGGraphics
-    : null;
-
 export {
   AbortException,
   AnnotationEditorLayer,

test/unit/pdf_spec.js

@@ -39,6 +39,7 @@ import {
   getDocument,
   PDFDataRangeTransport,
   PDFWorker,
+  SVGGraphics,
   version,
 } from "../../src/display/api.js";
 import {
@@ -110,10 +111,7 @@ describe("pdfjs_api", function () {
       renderTextLayer,
       setLayerDimensions,
       shadow,
-      SVGGraphics:
+      SVGGraphics,
-        typeof PDFJSDev !== "undefined" && PDFJSDev.test("LIB")
-          ? require("../../display/svg.js").SVGGraphics
-          : null,
       UnexpectedResponseException,
       updateTextLayer,
       Util,

test/unit/unit_test.html

@@ -17,6 +17,13 @@
         "pdfjs-web/": "../../web/",
         "pdfjs-test/": "../",
 
+        "display-fetch_stream": "../../src/display/fetch_stream.js",
+        "display-l10n_utils": "../../src/display/stubs.js",
+        "display-network": "../../src/display/network.js",
+        "display-node_stream": "../../src/display/stubs.js",
+        "display-node_utils": "../../src/display/stubs.js",
+        "display-svg": "../../src/display/stubs.js",
+
         "web-annotation_editor_params": "../../web/annotation_editor_params.js",
         "web-com": "../../web/genericcom.js",
         "web-pdf_attachment_viewer": "../../web/pdf_attachment_viewer.js",

web/viewer-geckoview.html

@@ -49,6 +49,13 @@ See https://github.com/adobe-type-tools/cmap-resources
           "pdfjs-lib": "../src/pdf.js",
           "pdfjs-web/": "./",
 
+          "display-fetch_stream": "../src/display/fetch_stream.js",
+          "display-l10n_utils": "../src/display/stubs.js",
+          "display-network": "../src/display/network.js",
+          "display-node_stream": "../src/display/stubs.js",
+          "display-node_utils": "../src/display/stubs.js",
+          "display-svg": "../src/display/stubs.js",
+
           "web-annotation_editor_params": "./stubs-geckoview.js",
           "web-com": "./genericcom.js",
           "web-pdf_attachment_viewer": "./stubs-geckoview.js",

web/viewer.html

@@ -60,6 +60,13 @@ See https://github.com/adobe-type-tools/cmap-resources
           "pdfjs-lib": "../src/pdf.js",
           "pdfjs-web/": "./",
 
+          "display-fetch_stream": "../src/display/fetch_stream.js",
+          "display-l10n_utils": "../src/display/stubs.js",
+          "display-network": "../src/display/network.js",
+          "display-node_stream": "../src/display/stubs.js",
+          "display-node_utils": "../src/display/stubs.js",
+          "display-svg": "../src/display/stubs.js",
+
           "web-annotation_editor_params": "./annotation_editor_params.js",
           "web-com": "./genericcom.js",
           "web-pdf_attachment_viewer": "./pdf_attachment_viewer.js",